Pharmaceutical Use of FAM19A5 Involved in Regulating Gliogenesis

ABSTRACT

The present invention relates to the pharmaceutical use of FAM19A5 involved in regulating gliogenesis, and more specifically, to the use of FAM19A5 in the prevention, diagnosis, or treatment of central nervous system injuries, degenerative brain diseases, or central nervous system diseases, FAM19A5 being spread in the neural stem cells in vertebrates and regulating gliogenesis.

BACKGROUND

1. Field of the Invention

The present invention relates to a pharmaceutical use of FAM19A5regulating proliferation and differentiation of neural stem cells invertebrates for diagnosing, preventing, or treating damage to thecentral nervous system, degenerative brain diseases, or central nervoussystem diseases.

2. Discussion of Related Art

A neural plate becomes a neural tube during early development, and acavity within neural tube forms a ventricle through the developmentalprocess. The cell layer closest to the ventricle is the ventricularzone. An additional proliferating cell layer is formed above theventricular zone through a neurogenesis process, which is referred to asthe subventricular zone. Progenitor cells in the ventricular zone andthe subventricular zone have properties of neural stem cells and migrateto a cortical plate through a complex control system [Dehay and Kennedy,Nat Rev Neurosci 8:438-450, 2007; Molyneaux et al., Nat Rev Neurosci8:427-437, 2007; Angevine and Sidman, Nature 192:766-768, 1961; Cavinessand Takahashi, Brain Dev 17:159-163, 1995].

Neural stem cells have an ability to divide continuously, that is, aself-renewal ability, and differentiate into neurons, astrocytes, andoligodendrocytes of the central nervous system. The differentiationprocess into neurons mainly occurs during the embryonic period, but thedifferentiation process into glial cells occurs after birth [Bayer etal., J Comp Neurol 307:499-516, 1991; Miller and Gauthier, Neuron54:357-369, 2007].

Differentiation from neural stem cells into neurons and glial cells is aphenomenon that is continuously observed in developmental process of thebrain and an adult's brain. In the adult brain, neurogenesis occurs intwo different brain regions, the subventricular zone of the lateralventricle and the dentate gyms of the hippocampus. In the subventricularzone, ependymal cells closest to the ventricle and astrocytesdistributed therealong serve as neural stem cells, and the two types ofcells become neuroblasts through transient amplifying cells [Doetsch,Curr Opin Genet Dev 13:543-550, 2003; Doetsch et al., Cell 97:703-716,1999; Lois and Alvarez-Buylla, Proc. Natl. Acad. Sci. USA 90:2074-2077,1993; Palmer et al., Mol Cell Neurosci 8:389-404, 1997; Temple, Nature414:112-117, 2001].

In order to maintain normal functions of the brain, a numerical balanceof neurons and glial cells is essential. In the past, astrocytes, whichaccounted for the majority of glial cells, were regarded as merelyprotective cells that aided neurons in performing their functions. Onthe contrary, astrocytes are now known to affect the environment aroundneurons beyond serving as a structural support. That is, astrocytessecrete growth factors, regulate functions of neurons, and help maintainthe barrier between blood vessels and the brain. Also, astrocytes areknown to play a more active role by directly regulating structureformation and synapse function between neurons [Nedergaard et al.,Trends Neurosci 26:523-530, 2003; Ullian et al., Science 291:657-661,2001; Song et al., Nature 417:39-44, 2002; Temple and Davis, Development120:999-1008, 1994; Seri et al., J Neurosci 21:7153-7160, 2001;Svendsen, Nature 417:29-32, 2002].

Functional significance of astrocytes is pathologically known through agreat deal of research. When the brain is damaged, astrocytes activelyproliferate, become reactive, and hypertrophy is observed. Activeproliferation of such glial cells is advantageous in that it promotesrecovery of tissues shortly after initial damage and prevents damagefrom spreading. However, when such a phenomenon is repeated,regeneration of neurons is suppressed and an inflammatory response iscaused, and damage is applied, which may result in degenerative braindisease [Myer et al., Brain 129:2761-2772, 2006; Chen and Swanson, JCereb Blood Flow Metab 23:137-149, 2003; Cunningham et al., Brian 128:1931-1942, 2005; Faden, Curr Opin Neurol 15:707-712, 2002; Katayama etal., J Neurosurg 73:889-900, 1990].

Gliosis is a phenomenon that commonly occurs in various pathologicalprocesses of the central nervous system and is caused byhyperproliferation and activation of astrocytes resulting from neuronaldamage. When damage is applied to the central nervous system, normalastrocytes become hypertrophic, reactive astrocytes that increasegeneration of an intermediate filament protein called glial fibrillaryacidic protein (GFAP). Various glial cells including reactive astrocytesundergo hyperproliferation after damage and a solid cell layer named aglial scar that is a product of the healing process is formed. Suchgliosis is observed in degenerative brain diseases includingHuntington's disease, Parkinson's disease, and Alzheimer's disease, incerebrospinal damage, and various pathological phenomena of the centralnervous system such as strokes and brain tumors [Faideau et al., Hum MolGenet, 2010; Chen et al., Curr Drug Targets, 2005; Rodriguez et al.,Cell Death Differ, 2009; Robel et al., J Neurosci, 2011; Talbott et al.,Exp Neurol, 2005; Shimada et al., J Neurosci; 2012; Sofroniew andVinters, Acta Neuropathol, 2010]

In general, gliosis has various influences depending on thecircumstances in which damage has initially occurred or the time thathas elapsed after a wound has occurred. After damage, initial reactiveastrocytes secrete nerve growth factors preventing programmed cell deathsuch as GDNF and cause resumption in the uptake of glutamic acid,thereby protecting neurons. In addition, the initial reactive astrocytespositively function in processes such as recovery of the blood-brainbarrier, isolating a region in which damage has occurred, and preventinginfection of healthy tissues. However, when a predetermined time elapsesafter damage, glia scars are formed by hyperproliferated reactiveastrocytes and surround a damaged region like a net, and an inhibitoryextracellular matrix accumulates. A dense structure of such proteinsserves as a barrier that prevents neurons from being physically andchemically regenerated and reconstructing connections. Also, substancesthat induce inflammation and neurotoxic substances such as cytotoxiccytokines are secreted to induce apoptosis of neurons, inhibitfunctional recovery, and worsen pathological symptoms. In the relatedart, central nervous system diseases may be detected through ahistopathological test, computerized tomography (CT), or magneticresonance imaging (MRI). However, diagnosis using such methods may bepossible only after the disease has progressed to some extent.Therefore, development of a diagnosis marker that may rapidly andaccurately identify the degree of progress of central nervous systemdisease is essential. Also, a method of treatment in which neuronssurvive at the early stage of damage and generation of glia scars isminimized and neuron regeneration is promoted at the later phase will bethe best method.

SUMMARY OF THE INVENTION

The present invention is directed to providing a pharmaceutical use ofFAM19A5 for diagnosing, preventing, or treating central nervous systemdamage, degenerative brain diseases, or central nervous system diseasesby identifying a role of FAM19A5 in regulating gliogenesis.

To solve the above-described objects, the present invention provides acomposition for regulating proliferation or differentiation of stemcells containing FAM19A5 (family with sequence similarity 19, member A5)or an inhibitor thereof as a proliferation or differentiation regulator.

The present invention also provides a composition for diagnosing centralnervous system damage, degenerative brain diseases, or central nervoussystem diseases, containing an agent for measuring mRNA of FAM19A5(family with sequence similarity 19, member A5) genes or a protein levelthereof

The present invention also provides a composition for treating earlytraumatic brain injury, containing FAM19A5 (family with sequencesimilarity 19, member A5).

The present invention also provides a use of FAM19A5 for preparing apharmaceutical composition for treating early traumatic brain injury.

The present invention also provides a method for treating earlytraumatic brain injury in animals, including administering a compositionfor treating early traumatic brain injury, containing a pharmaceuticallyeffective dose of FAM19A5 to a subject.

The present invention also provides a composition for preventing ortreating degenerative brain diseases or central nervous system diseases,containing an FAM19A5 (family with sequence similarity 19, member A5)inhibitor.

The present invention also provides a use of the FAM19A5 inhibitor forpreparing a pharmaceutical composition for preventing or treatingdegenerative brain diseases or central nervous system diseases.

The present invention also provides a method of treating degenerativebrain diseases or central nervous system diseases in animals, includingadministering a composition for preventing or treating degenerativebrain diseases or central nervous system diseases, containing apharmaceutically effective dose of the FAM19A5 inhibitor to a subject.

The present invention also provides a method of screening for preventiveor therapeutic medicine for brain diseases or central nervous systemdiseases, including:

contacting FAM19A5 (family with sequence similarity 19, member A5) geneswith a candidate material in vitro, and

determining whether the candidate material promotes or inhibitsexpression of the genes.

The present invention also provides a method of screening for apreventive or therapeutic medicine for brain diseases or central nervoussystem diseases, including:

contacting FAM19A5 (family with sequence similarity 19, member A5)proteins with a candidate material in vitro, and

determining whether the candidate material promotes or inhibits afunction or an activity of the protein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows amino acid sequences (A) of FAM19A5 peptides expressed fromFAM19A5 genes of various vertebrates and a phylogenetic tree (B).

FIG. 2 shows mRNA expression patterns (A) of FAM19A family genes invarious mouse tissues and mRNA expression patterns (B) of FAM19A familygenes for each developmental stage through reverse transcriptionpolymerase chain reaction (RT-PCR).

FIG. 3 shows the results obtained by measuring expression of FAM19A5mRNA in the ventricular zone and spinal cord of rats for eachdevelopmental stage using in situ hybridization.

FIG. 4 shows the results obtained by determining the binding specificityof FAM19A5-specific antibody and His-FAM19A5 proteins using Westernblotting (A) and immunocytochemistry (B).

FIG. 5 shows the results obtained by measuring expression of FAM19A5peptides in the ventricular zone of mouse for each developmental stageusing immunohistochemistry.

FIG. 6 shows the results obtained by measuring (A) expression of FAM19A5peptides in neural stem cells and progenitor cells in the subventricularzone of adult mouse, and (B) the degree of expression of FAM19A5peptides under differentiated conditions using immunohistochemistry.

FIG. 7 shows the results obtained by measuring expression of FAM19A5peptides in neurospheres developing in neural stem cells of mouse, usingimmunocytochemistry.

FIG. 8 shows the results obtained by measuring expression of FAM19A5 inneurospheres. (A) shows the results obtained throughimmunocytochemistry, (B) shows the results obtained through RT-PCR, and(C) shows the results obtained through a microarray.

FIG. 9 shows the results obtained by measuring the effect of thedifferentiation potential of neural stem cells caused by FAM19A5 and aspecific antibody thereof using immunocytochemistry (A) and Westernblotting (B).

FIG. 10 shows the results obtained by measuring the effect of theproliferation potential of neural stem cells caused by FAM19A5 and aspecific antibody.

FIG. 11 shows the results obtained by measuring changes in FAM19A5proteins in the traumatic brain injury model in mouse usingimmunohistochemistry (I) and Western blotting (II) (A), and in bloodusing radioimmunoassay (B).

FIG. 12 shows the results obtained by measuring changes in FAM19A5proteins over time after traumatic brain injury.

FIG. 13 shows the results obtained by measuring changes in FAM19A5proteins in an amyotrophic lateral sclerosis model usingimmunohistochemistry (A), Western blotting (B), and radioimmunoassay(C).

FIG. 14 shows the fluorescence signal in brain tissues when treated withFAM19A5-specific antibodies after traumatic brain injury.

FIG. 15 shows changes in cell markers over time when treated withFAM19A5-specific antibodies after traumatic brain injury.

FIG. 16 shows changes in neurons when treated with FAM19A5-specificantibodies after traumatic brain injury.

FIG. 17 shows the results obtained by determining positions of reactiveastrocytes expressing FAM19A5 proteins in the traumatic brain injurymodel in mouse treated with FAM19A5-specific antibodies.

FIG. 18 shows the results obtained by measuring changes in NG2oligodendrocyte progenitor cells (A) and oligodendrocyte cells (B) whentreated with FAM19A5-specific antibodies after traumatic brain injury.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Unless particularly defined otherwise, all terms including technical andscientific terms used herein have the same meaning as commonlyunderstood by one of ordinary skill in the art to which this inventionbelongs. In general, the nomenclatures used in this specification andthe experimental methods described below are widely known and generallyused in the related art.

FAM19A5 (family with sequence similarity 19, member A5) is a member ofFAM19A family genes composed of five highly homologous genes that encodesmall secretory proteins. These proteins contain conserved cysteineresidues at fixed positions, and are related to MIP-1 alpha which is amember of the CC-chemokine gene family. It is known that these proteinsare predominantly expressed mainly in the brain and the spinal cord,generated and secreted in neurogenesis processes and by adult neuralstem cells, and serve as a differentiation regulating factor forpromoting generation of astrocytes.

The inventors found the presence of FAM19A5 in the body through abioinformatics approach and by using in situ hybridization andimmunohistochemistry, identified a role of FAM19A5 in a process ofgenerating cells differentiated from neural stem cells usingimmunocytochemistry, and determined a therapeutic use regarding severaldiseases related to neurons and gliogenesis in vertebrates, and havecompleted the present invention.

Therefore, the present invention provides a composition for regulatingproliferation or differentiation of stem cells, containing FAM19A5(family with sequence similarity 19, member A5) as a proliferation ordifferentiation regulator.

According to a detailed example of the present invention, FAM19A5 ispredominantly expressed in the brain of vertebrates, and particularly,strongly distributed in the ventricular zone and spinal cord region,highly expressed in the ventricular zone and the subventricular zone ofeven fetus in pregnancy before birth, but weakly expressed in thecortical plate at which differentiated neurons are positioned.Therefore, the present invention has demonstrated for the first timethat FAM19A5 genes are strongly expressed in two regions of the centralnervous system known to have a population of neural stem cells,important in formation of a complete central nervous system, andinvolved in generation of neurons and glial cells constituting thecentral nervous system.

Based on these results, expression of FAM19A5 in neurospheres developedfrom neural stem cells has been observed. As a result, it can be shownthat FAM19A5 is distributed much more in neurospheres than other typesof FAM19A family genes. This suggests that FAM19A5 may be an importantpeptide in the functions of adult and embryonic neural stem cells and inthe differentiation process into different types of cells generatedtherefrom.

Through these results, it has been determined that FAM19A5 is generatedand secreted from neural stem cells, that it influences generation ofcells (that is, neurons or astrocytes), and their differentiation. As aresult, it can be seen that FAM19A5 promotes generation of astrocytes.

Therefore, FAM19A5 may regulate the number of neurons or astrocytesdifferentiated from neural stem cells through a quantitative change intheir number. That is, since the number of differentiated astrocytesincreases through a quantitative increase in FAM19A5 and the number ofdifferentiated neurons increases through a quantitative reduction inFAM19A5, it can be seen that FAM19A5 is a differentiation regulatingfactor.

In addition, according to another detailed example of the presentinvention, it has been determined that proliferation of neural stemcells decreases through a quantitative increase in FAM19A5 andproliferation of neural stem cells increases through a quantitativereduction in FAM19A5. Therefore, it can be seen that FAM19A5 is aproliferation regulating factor of stem cells.

Therefore, FAM19A5 or an inhibitor thereof may be used as aproliferation or differentiation regulator of stem cells.

FAM19A5 of the present invention is a secretory protein secreted fromneural stem cells, it includes gene sequences encoding a typical signalpeptide of an amino-terminus as a signal that can be extracellularlysecreted, and has amino acid sequences of mature FAM19A5, subsequently(refer to FIG. 1).

A composition for regulating proliferation or differentiation of stemcells of the present invention may include natural or recombinantFAM19A5, FAM19A5 proteins having substantial physiological activitythereto, transgenic neural stem cells overexpressing the natural orrecombinant FAM19A5, or an FAM19A5 inhibitor. The protein havingsubstantially equivalent physiological activity includesnatural/recombinant FAM19A5, a functional equivalent thereof, and afunctional derivative.

The term “functional equivalent” refers to an amino acid sequencevariant in which some or all of amino acids of the natural protein aresubstituted or some amino acids are deleted or added, and that hassubstantially equivalent physiological activity to that of naturalFAM19A5.

The term “functional derivative” refers to a protein that has beenmodified to increase or decrease physical and chemical properties of theFAM19A5 protein and has substantially equivalent physiological activityto that of natural FAM19A5.

The FAM19A5 protein of the present invention originates mostly frommammals, such as, humans, mice, rats, and the like; zebra finches,chickens, zebra danios, frogs, sticklebacks, and the like, and refers toa protein having a known sequence, for example, human-derived GenBankaccession no. NM_(—)134096, NM_(—)001191991.

According to a detailed example, FAM19A5 used in the present inventionmay be prepared by a genetic engineering method that is known to thoseskilled in the art from GenBank accession no. NM_(—)134096,NM_(—)001191991, and the like.

When a protein is prepared by a gene recombinant method to obtainnatural FAM19A5, if mammal cells are used instead of E. coli or insectcells, it is considered to be more similar to the natural type in termsof the degree of activity or solubility of the protein.

The recombinant FAM19A5 protein may be isolated using a typical columnchromatography method. The degree of purification of the protein may bedetermined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE).

The transgenic neural stem cells overexpressing the natural orrecombinant FAM19A5 may be prepared by introducing a vector expressingnatural or recombinant FAM19A5 into neural stem cells through a knownmethod.

The FAM19A5 inhibitor may be any one of an antisense-oligonucleotide,siRNA, shRNA, miRNA or a vector including the same, or antibodies.

The composition for regulating proliferation or differentiation of stemcells of the present invention may be added as a proliferation ordifferentiation regulating factor when neural stem cells are cultured invitro. For example, in a proliferation or differentiation-inducingculture of neural stem cells, natural or recombinant FAM19A5 or aninhibitor thereof is added such that an increase or decrease of stemcell proliferation may be regulated through a quantitative changethereof or the number of neurons or astrocytes may be regulated.

In addition, when neural stem cells and transgenic neural stem cellsoverexpressing natural or recombinant FAM19A5 are co-cultured to inducedifferentiation, the number of astrocytes may increase due to increasesin amounts of FAM19A5 proteins secreted from transgenic and regularneural stem cells.

The composition for regulating proliferation or differentiation of stemcells of the present invention may further include a knowndifferentiation-inducing factor that induces differentiation of neuralstem cells in addition to FAM19A5. For example, a ciliary neurotrophicfactor (CNTF), bone morphogenetic proteins (BMPs), a transforming growthfactor (TGFα), or a neuregulin-1 (Nrg1)/glial growth factor-2(GGF2) maybe used.

The present invention also provides a composition for diagnosing centralnervous system damage, degenerative brain diseases, or central nervoussystem diseases, containing an agent for measuring mRNA expression orprotein concentration of FAM19A5 (family with sequence similarity 19,member A5).

When the brain is damaged, mature astrocytes actively proliferate,change to reactive astrocytes, become hypertrophic, induce rapidrecovery of tissues, and prevent damage from spreading.

According to a detailed example of the present invention, FAM19A5expression significantly increases in a damaged region, radial glialcells in the damaged region express nestin, serving as a marker andsimultaneously express FAM19A5, and significantly numerically increasecompared to an undamaged control group. In addition, neuroblastsmigrating to a brain injury region from the subventricular zone throughthe corpus collosum express little or no FAM19A5. In addition to thedamaged region, the number of cells expressing FAM19A5 proteinsincreases in a periphery region of the subventricular zone in which aneural stem cell population is positioned, and these simultaneouslyexpress GFAP serving as a marker of astrocytes.

In addition, FAM19A5 may leak into blood while the blood-brain barrieris damaged after a brain injury. The presence of FAM19A5 can bedetermined by a blood test. The amount of such expression tends tocontinuously increase over time after brain injury.

According to another detailed example of the present invention, aquantitative change in FAM19A5 protein concentration is measured inamyotrophic lateral sclerosis which is a spinal cord damage diseasemodel. As a result, it was determined that the amount of expressionincreased compared to a normal model.

Therefore, FAM19A5 may be used as a biomarker for diagnosing centralnervous system damage.

Also, according to another detailed example of the present invention,when FAM19A5-specific antibodies are used to treat reactive astrocytesgenerated due to traumatic brain injury, excessive proliferation ofthose astrocytes is inhibited, neurons survive, and therefore, promotionof the regeneration of neurons of the damaged region is expected in thelong run. Accordingly, FAM19A5 may be used to objectively andquantitatively diagnose a progress state of disease caused by centralnervous system damage.

Therefore, FAM19A5 may be used as a biomarker for diagnosingdegenerative brain disease due to central nervous system damage orcentral nervous system disease.

The term “central nervous system damage” in this specification includesall types of central nervous system damage causing destruction ordegeneration of cerebrospinal cells. Traumatic brain injury, amyotrophiclateral sclerosis, and the like may be exemplified, but the damage isnot limited thereto.

The term “degenerative brain disease or central nervous system disease”refers to degenerative brain disease or central nervous system diseasecaused by gliosis resulting from damage of the central nervous system.Examples of such disease include Alzheimer's disease, Huntington'sdisease, Parkinson's disease, stroke, or brain tumor, but the disease isnot limited to any specific type of disease.

The term “diagnosis” refers to determination of a pathologic state. Inview of the object of the present invention, the diagnosis refers to thefact that expression of FAM19A5, a diagnosis marker of central nervoussystem damage, degenerative brain disease, or central nervous systemdisease is determined to identify occurrence, progress, and alleviationof central nervous system damage, degenerative brain disease, andcentral nervous system disease.

The term “diagnosis marker” refers to a material capable of separatelydiagnosing cells of central nervous system damage, degenerative braindisease, or central nervous system disease from normal cells, andincludes organic bio-molecules such as polypeptides, or nucleic acids(for example, mRNA), lipids, glycolipids, glycoproteins, and sugars(monosaccharides, disaccharides, oligosaccharides, and the like) whichincrease or decrease in cells of central nervous system damage,degenerative brain disease, or central nervous system disease, comparedto normal cells. The diagnosis marker provided in the present inventionfor central nervous system damage, degenerative brain disease, orcentral nervous system disease may be a protein that is expressed fromFAM19A5 genes of which the expression increases in cells of centralnervous system damage, degenerative brain disease, or central nervoussystem disease, compared to normal cells.

The composition for diagnosing central nervous system damage,degenerative brain disease, or central nervous system disease of thepresent invention includes an agent for measuring the expression levelof mRNA of FAM19A5 genes or the amount of protein expressed. As such anagent, oligonucleotides having a sequence complementary to FAM19A5 mRNA,for example, a primer or a nucleic acid probe that specifically binds toFAM19A5 mRNA, and antibodies specific to FAM19A5 proteins may beincluded.

The primer refers to a single-stranded oligonucleotide that may serve asa starting point of template-directed DNA synthesis under appropriateconditions (that is, four types of different nucleoside triphosphatesand polymerization enzymes) in an appropriate temperature and anappropriate buffer solution. The appropriate length of the primer may bechanged by various factors, for example, temperature, and usage of theprimer. Also, the sequence of the primer need not have a completelycomplementary sequence to the sequence of the template. It is sufficientthat the sequence have sufficient complementarity in a range in whichsequences may be hybridized and the function of the primer may beperformed. Therefore, the primer of the present invention need not havea completely complementary sequence to the nucleotide sequence of thegenes serving as the template. It is sufficient that the sequence havesufficient complementarity in a range in which sequences hybridize andthe function of the primer may be performed. Also, the primer of thepresent invention may be preferably used in gene amplificationreactions. The amplification reaction refers to a reaction of amplifyingnucleic acid molecules. Such amplification reactions of genes arewell-known in the related art, and may include, for example, polymerasechain reaction (PCR), reverse transcription polymerase chain reaction(RT-PCR), ligase chain reaction (LCR), transcription-mediatedamplification (TMA), and nucleic acid sequence based amplification(NASBA).

The nucleic acid probe, which refers to a natural or modified monomer ora linear linked oligomer including a deoxyribonucleotide and aribonucleotide, is able to specifically hybridize with a targetnucleotide sequence, and is naturally occurring or artificiallysynthesized. The probe, according to the present invention, may be asingle chain, and preferably, be an oligodeoxyribonucleotide. The probeof the present invention may include natural dNMP (that is, dAMP, dGMP,dCMP, and dTMP), and nucleotide analogues or derivatives. Also, theprobe of the present invention may include a ribonucleotide. Forexample, it may include backbone-modified nucleotides, such as, peptidenucleic acid (PNA) (M. Egholm et al., Nature, 365:566-568 (1993)),phosphorothioate DNA, phosphorodithioate DNA, phosphoramidate DNA,amide-linked DNA, MMI-linked DNA, 2′-O-methyl RNA, alpha-DNA andmethylphosphonate DNA, a sugar-modified nucleotide for example,2′-O-methyl RNA, 2′-fluoro RNA, 2′-amino RNA, 2′-O-alkyl DNA, 2′-O-allylDNA, 2′-O-alkynyl DNA, hexose DNA, pyranosyl RNA and anhydrohexitol DNA,nucleotides having a nucleotide variation, for example, C-5 substitutedpyrimidine (a substituent includes fluoro-, bromo-, chloro-, iodo-,methyl-, ethyl-, vinyl-, formyl-, ethnyl-, propynyl-, alkynyl-,thiazolyl-, imidazolyl-, and pyridyl-), 7-deazapurine having a C-7substituent (a substituent includes fluoro-, bromo-, chloro-, iodo-,methyl-, ethyl-, vinyl-, formyl-, alkynyl-, alkenyl-, thiazolyl-,imidazolyl-, and pyridyl-), inosine, and diaminopurine.

As antibodies specific to FAM19A5, polyclonal antibodies, monoclonalantibodies, human antibodies, and humanized antibodies may be used.

Examples of fragments of the antibody include Fab, Fab′, F(ab′)2, and Fvfragments; a diabody; linear antibodies (Zapata et al., Protein Eng.8(10):1057-1062(1995)); single chain antibody molecules; multispecificantibodies formed from antibody fragments, and the like.

When antibodies are decomposed by papain, two identical antigen-bindingfragments, “Fab” fragment having a single antigen binding site and theremaining “Fc” fragment, are generated. When pepsin treatment occurs, anF(ab′)2 fragment having two antigen binding sites and still capable ofcross-linking to the antigen is generated. Fv is a small antibodyfragment produced that includes a complete antigen recognizing andbinding region. This region is composed of a dimer of one heavy chainand one light chain variable region, and is tightly coupled bynon-covalent bonds.

A method of preparing polyclonal antibodies is known for those skilledin the art. Polyclonal antibodies may be prepared by injecting animmunizing agent into mammals one or more times, and as necessary, animmunoadjuvant may be simultaneously injected. Typically, the immunizingagent and/or the immunoadjuvant are subcutaneously or intraperitoneallyinjected into mammals several times. The immunizing agent may be aprotein of the present invention or a fusion protein thereof. When aprotein known to have immunogenicity and the immunizing agent areinjected together into mammals to be immunized, it may be effective.

The monoclonal antibodies featured in the present invention may beprepared by a hybridoma method described in the document (Kohler et al.,Nature, 256:495 (1975)), or prepared by a recombinant DNA method (forexample, refer to U.S. Pat. No. 4,816,576). For example, the monoclonalantibodies may also be isolated from a phage antibody library using atechnique described in the document (Clackson et al., Nature,352:624-628 (1991) and Marks et al., J. Mol. Biol., 222:581-597 (1991)).

The monoclonal antibodies of the present invention specifically include“chimera” antibodies in which a part of a heavy chain and/or a lightchain has an identical or homologous sequence corresponding toantibodies derived from specific species or antibodies belonging to aspecific antibody class or subclass, but the rest of the chain(s) hasantibodies derived from different species, or antibodies belonging to adifferent antibody class or subclass, or is identical or homologous tofragments of such antibodies, as long as a desired activity is exhibited(Morrison et al., Proc. Natl. Acad. Sci. USA, 81:6851-6855(1984)).

“Humanized” types of non-human (for example, the Murinae) antibodiesinclude a chimera immunoglobulin having a minimum sequence derived froma non-human immunoglobulin, an immunoglobulin chain, or fragmentsthereof (for example, Fv, Fab, Fab′, F(ab′)2 or other antigen bindingsequences of antibodies). In most cases, the humanized antibodiesinclude a human immunoglobulin (receptor antibodies) in which a residueof a complementarity determining region (CDR) of a receptor issubstituted with a CDR residue of non-human species (donor antibodies),such as rats, mice, or rabbits, which have a desired specificity,affinity, and capability. In some cases, an Fv framework residue of thehuman immunoglobulin is substituted with a corresponding non-humanresidue. Also, the humanized antibodies may include receptor antibodiesor a residue not found in the introduced CDR or framework sequence. Ingeneral, the humanized antibodies substantially include at least one,and generally, two or more variable domains. Here, all or substantiallyall CDR regions correspond to regions of the non-human immunoglobulin,and all or substantially all FR regions correspond to regions of humanimmunoglobulin sequences. In addition, the humanized antibodies includeat least a part of an immunoglobulin constant region (Fc), andgenerally, a part of a human immunoglobulin region (Presta, Curr. Op.Struct. Biol. 2:593-596(1992)).

The composition for diagnosing central nervous system damage,degenerative brain disease, or central nervous system disease of thepresent invention may be included in the form of a kit.

The kit may include the primer, the probe, or the antibodies that may beused to measure the expression level of FAM19A5 genes or an amount ofproteins. Definitions thereof are the same as those in the abovedescription.

When the kit is applied to a PCR amplification process, reagentsnecessary for PCR amplification, for example, a buffer solution, DNApolymerase (for example, thermostable DNA polymerase obtained fromThermus aquaticus (Taq), Thermus thermophiles (Tth), Thermus filiformis,Thermis flavus, Thermococcus literalis or Pyrococcus furiosus (Pfu)), aDNA polymerase cofactor, and dNTPs may be optionally included. When thekit is applied to an immunoassay, it may optionally include secondaryantibodies and a labeled substrate. Further, the kit according to thepresent invention may be manufactured in multiple separate packages orcompartments including the above reagent components.

Also, the composition for diagnosing central nervous system damage,degenerative brain disease, or central nervous system disease of thepresent invention may be included in the form of a microarray.

In the microarray of the present invention, the primer, the probe, orthe antibodies that may be used to measure the expression level of theFAM19A5 protein or gene encoding the protein are used as hybridizablearray elements, and fixed on a substrate. A preferred substrate mayinclude, for example, a film, a filter, a chip, a slide, a wafer, afiber, a magnetic bead or nonmagnetic bead, gel, tubing, a plate, apolymer, a microparticle, or a capillary, as an appropriately robust ornon-robust support. The hybridizable array elements are arranged andfixed on the substrate. Such fixation may be performed by a chemicalbonding method or a covalent method involving UV. For example, thehybridizable array element may be coupled to a glass surface that ismodified to include an epoxy compound or an aldehyde group, or becoupled to a polylysine coating surface by UV. In addition, thehybridizable array element may be coupled to the substrate through alinker (for example: an ethylene glycol oligomer and diamine)

Meanwhile, when a sample applied to the microarray of the presentinvention is a nucleic acid, the sample may be labeled and hybridizedwith an array element on the microarray. Hybridization conditions may bevariable, and detection and analysis of a degree of hybridization may bevariously performed according to a labeling material.

Also, the present invention provides a method of diagnosing centralnervous system damage, degenerative brain disease, or central nervoussystem disease using a method of measuring the expression level of theFAM19A5 gene or protein, and more specifically, the method includes (a)measuring the expression level of FAM19A5 genes or the amount ofexpressed protein from a biological sample of a patient suspected ofhaving central nervous system damage, degenerative brain disease, orcentral nervous system disease; and (b) measuring the expression levelof genes or the amount of expressed protein from a normal control groupsample and comparing the result with the measurement result of (a).

A method of measuring an expression level of genes or an amount ofprotein in the above description may use a known technique, including aknown process of separating mRNA or proteins from a biological sample.

The biological sample refers to a sample collected from a body that hasa different gene or protein expression level compared to the occurrenceor a degree of progress of central nervous system damage, degenerativebrain disease, or central nervous system disease from a normal controlgroup. Examples of the sample may include tissue, cells, blood, serum,plasma, saliva, and urine, but the sample is not limited thereto.

When the expression level of the genes is measured, the level of mRNA ispreferably measured. As a method of measuring the level of mRNA, RT-PCR,real time RT-PCR, an RNase protection assay, a Northern blot, a DNAchip, and the like may be used, but the method is not limited thereto.

When the protein level is measured, antibodies may be used. In thiscase, the FAM19A5 protein in a biological sample and antibodies specificthereto form a conjugate, that is, an antigen-antibody complex. Theamount of antigen-antibody complex generated may be quantitativelymeasured by the size of the signal produced by a detection label. Such adetection label may be selected from a group consisting of an enzyme, afluorescent material, a ligand, a light-emitting material, amicroparticle, a redox molecule, or a radioactive isotope, but the labelis not limited thereto. An analysis method of measuring a protein levelincludes a Western blot, ELISA, radioimmunoassay analysis,radioimmunodiffusion, an Ouchterlony immunodiffusion method, rocketimmunoelectrophoresis, tissue immunostaining, an immunoprecipitationassay, a complement fixation assay, FACS, a protein chip, and the like,but the method is not limited thereto.

Therefore, using the detection methods, the present invention maydetermine the amount of mRNA or protein expressed in a control group,and the amount of mRNA or protein expressed in a patient suspected ofhaving central nervous system damage, degenerative brain disease, orcentral nervous system disease. The results can then be compared witheach other to diagnose occurrence, the degree of progress, and the likeof central nervous system damage, degenerative brain disease, or centralnervous system disease.

Also, in the method of diagnosing central nervous system damage,degenerative brain disease, or central nervous system disease accordingto the present invention, when the expression level of the FAM19A5 genesor the amount of the expressed proteins, according to the presentinvention increases compared to the normal control group sample, it maybe determined that central nervous system damage, degenerative braindisease, or central nervous system disease is present.

The present invention also relates to a composition for treating earlytraumatic brain injury containing FAM19A5 (family with sequencesimilarity 19, member A5).

The present invention also provides a use of FAM19A5 for preparing apharmaceutical composition for treating early traumatic brain injury.

Initial reactive astrocytes generated after damage due to traumaticbrain injury secrete a nerve growth factor that prevents programmed celldeath, such as GDNF, and resumes the uptake of glutamic acid to protectneurons. Also, the astrocytes beneficially function by recoveringfunction of the blood-brain barrier, isolating a region in which damagehas occurred, and preventing infection of healthy tissues.

Since FAM19A5 generated from neural stem cells is involved in generationof astrocytes rather than neurons, FAM19A5 may promote generation ofastrocytes in a brain injury region to treat early brain injury andinhibit the progression of brain injury disease.

Therefore, FAM19A5 may be used as an agent for treating early traumaticbrain injury.

A composition for treating early traumatic brain injury of the presentinvention may include at least one natural or recombinant FAM19A5protein, FAM19A5 proteins having substantially equivalent physiologicalactivity thereto, transgenic neural stem cells overexpressing FAM19A5proteins, or astrocytes differentiated from the neural stem cells.Definitions thereof are the same as those in the above description. Thenatural or recombinant FAM19A5 proteins or FAM19A5 proteins havingsubstantially equivalent physiological activity thereto promotegeneration of astrocytes in a brain injury region to treat earlytraumatic brain injury.

Also, the transgenic neural stem cells overexpressing the FAM19A5protein are directly injected into brain tissue and FAM19A5 proteins aresecreted in a brain injury region to promote generation of astrocytes,or promote differentiation from the transgenic neural stem cells intoastrocytes to treat early traumatic brain injury. In this case, in orderto promote differentiation of the transgenic neural stem cells, adifferentiation-inducing factor may be co-administered. Types ofdifferentiation-inducing factor are the same as those in the abovedescription.

When astrocytes differentiated from neural stem cells are directlyinjected into brain tissue and a large amount of astrocytes are presentin a brain injury region, early traumatic brain injury may be treated.

Also, the present invention provides a method of treating earlytraumatic brain injury of an animal including administering acomposition for treating early traumatic brain injury containing apharmaceutically effective dose of FAM19A5 to a subject.

A pharmaceutical composition and an administration method used in themethod of treating early brain injury will be described below, redundantdescriptions will not be provided in order to avoid excessive complexityof the present specification.

A subject, into which the composition for treating early traumatic braininjury may be administered, includes all animals, such as dogs, cats,and rats.

The present invention also relates to a composition for preventing ortreating degenerative brain disease or central nervous system diseasecontaining an FAM19A5 (family with sequence similarity 19, member A5)inhibitor.

The present invention also provides a use of the FAM19A5 inhibitor forpreparing a pharmaceutical composition for preventing or treatingdegenerative brain disease or central nervous system disease.

Since FAM19A5 promotes generation of astrocytes, which are a type ofglial cell, when expression of FAM19A5 mRNA or protein is inhibited indegenerative brain disease or central nervous system disease, in which alarge amount of glial cells is expressed, the number of reactiveastrocytes decreases due to FAM19A5 inhibition, and proliferation ofprogenitor cells expressing NG2 (neuron-glial antigen 2) is promoted,axons of neurons near a brain injury region are myelinated, and therebyan FAM19A5 inhibitor may be used to treat degenerative brain disease orcentral nervous system disease.

Therefore, the composition for preventing or treating degenerative braindisease or central nervous system disease of the present invention mayinclude an agent for decreasing mRNA expression of FAM19A5 genes orexpression of protein thereof, or a function or an activity.

The FAM19A5 protein inhibitor may be a peptide or a compound that iscoupled to FAM19A5 proteins and regulates a signal of a neuraldifferentiation path. Such an inhibitor may be selected by the followingexemplified screening method such as a protein structure analysis, andmay be designed using a known method in the related art.

Also, the protein inhibitor may use polyclonal antibodies, monoclonalantibodies, human antibodies, and humanized antibodies for FAM19A5proteins, and definitions of the antibodies are the same as those in theabove description.

When signal transduction of a neural differentiation pathway ofreceptors in cells is regulated using the antibodies, degenerative braindisease or central nervous system disease may be prevented or treated.

A function or activity inhibitor of FAM19A5 protein of the presentinvention may be delivered by liposomes, viruses, a gene gun, a polymer,ultrasound, or electric shock, but the delivery method is not limitedthereto.

The FAM19A5 genes may be DNA encoding the gene or mRNA transcriptedtherefrom. Therefore, the inhibitor of the genes may be an inhibitorthat is coupled to the gene itself to prevent transcription or coupledto mRNA transcripted from the gene to prevent translation of the mRNA.

Therefore, the inhibitor of the FAM19A5 gene includes all inhibitorsthat suppress expression of FAM19A5 genes. For example, such aninhibitor may be a peptide, nucleic acid, a compound, and the likecoupled to the gene. The inhibitor may be selected by the followingexemplified screening method such as cell-based screening, and may bedesigned using a known method in the related art.

In a detailed example, the inhibitor may be anantisense-oligonucleotide, siRNA, shRNA, miRNA, or a vector includingthe same of FAM19A5 genes. Such an antisense-oligonucleotide, siRNA,shRNA, miRNA and a vector including the same may be prepared using aknown method in the related art.

The term “siRNA” in the present specification refers to double-strandedRNA molecules inducing RNA interference through cutting the mRNA of atarget gene, and requires an RNA strand of a sense sequence having thesame sequence as mRNA of the target gene and an RNA strand of anantisense sequence having a sequence complementary thereto.

The siRNA may include the siRNA itself synthesized in vitro or a formthat is expressed by inserting a sequence encoding siRNA into anexpression vector.

In the present invention, the term “vector” refers to a gene constructincluding external DNA inserted into a genome encoding a polypeptide.

The vector related to the present invention is a vector in which anucleic acid sequence inhibiting the gene is inserted into a genome.Examples of a vector may include a DNA vector, a plasmid vector, acosmid vector, a bacteriophage vector, a yeast vector, or a virusvector.

Also, the antisense strand has a sequence complementary to the FAM19A5gene or all or some mRNA sequences transcripted from fragments thereofand couples to the mRNA to inhibit expression of the FAM19A5 gene orfragments thereof

Also, short hairpin RNAi (shRNAi) may be prepared by targeting a commonshRNAi sequence area of humans or rats using a general method.

Also, the composition for preventing or treating degenerative braindisease or central nervous system disease of the present invention mayfurther include embryonic neural stem cells or adult neural stem cellsin addition to the FAM19A5 inhibitor. Since the FAM19A5 inhibitorregulates proliferation and differentiation of neural stem cells, usedtogether they promote generation of neurons helping tissue recovery, sotreatment of degenerative brain disease or central nervous systemdisease may be further improved.

The present invention also provides a method of treating degenerativebrain disease or central nervous system disease of an animal, includingadministering a composition for preventing or treating degenerativebrain disease or central nervous system disease containing apharmaceutically effective dose of the FAM19A5 inhibitor to a subject.

Since the pharmaceutical composition and the administration method usedin the treatment of degenerative brain disease or central nervous systemdisease have been already described above, redundant description willnot be provided in order to avoid excessive complexity of the presentspecification.

Meanwhile, a subject to which the pharmaceutical composition forpreventing or treating degenerative brain disease or central nervoussystem disease may be administered may include all animals, for example,non-human animals such as dogs, cats, and rats.

Also, a medicine composition of the present invention may furtherinclude a pharmaceutically acceptable carrier.

The pharmaceutically acceptable carrier includes a carrier and a vehiclethat are commonly used in the field of medicine, and specifically,includes an ion exchange resin, alumina, aluminum stearate, lecithin, aserum protein (for example, human serum albumin), a buffer material (forexample, various phosphates, glycine, sorbic acid, potassium sorbate,and a partial glyceride mixture of saturated vegetable fatty acid),water, salts or electrolytes (for example, protamine sulfate, disodiumhydrogen phosphate, potassium hydrogen phosphate, sodium chloride, andzinc salts), colloidal silica, magnesium trisilicate,polyvinylpyrrolidone, a cellulosic substrate, a polyethylene glycol,sodium carboxymethyl cellulose, polyarylate, wax, a polyethylene glycol,lanolin, and the like, but the carrier is not limited thereto.

Also, the composition of the present invention may further include alubricant, a wetting agent, an emulsifying agent, a suspending agent, apreservative, and the like in addition to the above components.

As an aspect, the composition according to the present invention may beprepared as an aqueous solution for parenteral administration.Preferably, Hank's solution, Ringer's solution, or a buffer solutionsuch as a physically buffered salt solution, may be used. An aqueousinjection suspension may include a substrate that may increase theviscosity of the suspension such as sodium carboxymethyl cellulose,sorbitol, or dextran.

The composition of the present invention may be systemically or locallyadministered and may be formulated in an appropriate formulation using aknown technique for administration. For example, when the composition isadministered orally, the composition may be mixed with an inert diluentor an edible carrier, sealed in a hard or soft gelatin capsule, orcompressed into a tablet, and then administered. In oral administration,the active compound may be mixed with an excipient and used in the formof an intake tablet, a buccal tablet, a troche, a capsule, an elixir, asuspension, syrup, a wafer, and the like.

Various formulations for injection, parenteral administration, and thelike may be prepared by a known technique in the related art or acommonly used technique. Since FAM19A5 is very soluble in a saline or abuffer solution, FAM19A5 is stored in a freeze-dried state, and then aneffective dose of FAM19A5 may be formulated in a saline or a buffersolution for administration in an appropriate form for intravenousinjection, subcutaneous injection, intramuscular injection,intraperitoneal injection, percutaneous administration, and the likeimmediately before administration.

An effective dose of the active ingredient of the medicine compositionof the present invention refers to an amount that is necessary toprevent, inhibit, or alleviate disease.

Therefore, the effective dose may be regulated according to variousfactors such as disease type, severity of disease, the active ingredientcontained in the composition and types and contents of other components,types of formulation, a patient's age, weight, general health condition,and gender, diet, administration time, administration route, secretionrate of the composition, treatment period, and medicine used by thepatient at the same time. For example, when administration is performedonce or several times a day in adults and the inhibitor of the presentinvention is administered once or several times a day, 0.1 ng/kg to 10g/kg of a compound, 0.1 ng/kg to 10 g/kg of polypeptides, proteins orantibodies, and 0.01 ng/kg to 10 g/kg of an antisense-oligonucleotide,siRNA, shRNAi, or miRNA may be administered, but the dose is not limitedthereto.

The present invention also provides a method of screening for apreventive or therapeutic medicine for brain disease or central nervoussystem disease, including contacting FAM19A5 (family with sequencesimilarity 19, member A5) genes with a candidate material in vitro, anddetermining whether the candidate material promotes or inhibitsexpression of the genes.

The present invention also provides a method of screening a preventiveor therapeutic medicine for brain disease or central nervous systemdisease, including contacting FAM19A5 (family with sequence similarity19, member A5) proteins with a candidate material in vitro, anddetermining whether the candidate material promotes or inhibits afunction or an activity of the protein.

According to the screening method of the present invention, first, acandidate material to be analyzed comes in contact with cells of braindisease or central nervous system disease including the gene or protein.

According to a conventional selecting method, the candidate material mayinclude a material promoting or inhibiting transcription into mRNA andtranslation into proteins in FAM19A5 gene sequences, a material proposedto have a possible medical application promoting or inhibiting afunction or an activity of FAM19A5 proteins, or randomly selectedindividual nucleic acids, proteins, peptides, other extracts, naturalproducts, compounds, and the like.

Then, the amount of gene expression, the amount of protein, or activityof protein may be measured in candidate material-treated cells. In themeasurement result, when an increase or a decrease in the amount of geneexpression, the amount of protein, or the activity of the protein ismeasured, the candidate material may be determined as a material capableof treating or preventing brain disease or central nervous systemdisease.

In the above description, measurement of the amount of gene expression,the amount of protein, or the activity of the protein may be performedby various methods known in the related art, for example, RT-PCR, realtime polymerase chain reaction, a Western blot, a Northern blot, anenzyme linked immunosorbent assay (ELISA), radioimmunoassay analysis(RIA), radioimmunodiffusion, an immunoprecipitation assay, and the like,but the method is not limited thereto.

A candidate material exhibiting an activity promoting gene expression orpromoting a function of proteins, and conversely, a candidate materialexhibiting an activity inhibiting gene expression or inhibiting afunction of proteins are obtained by the screening method of the presentinvention. The former material may be a candidate material of atherapeutic agent for early traumatic brain injury. The later materialmay be a candidate material of a therapeutic agent for degenerativebrain disease or central nervous system disease.

Such a therapeutic agent candidate material for degenerative braindisease or central nervous system disease may serve as a leadingcompound in the later development process of a therapeutic agent fordegenerative brain disease or central nervous system disease. When theleading compound transforms and optimizes a structure thereof such thatfunctions of FAM19A5 genes or proteins expressed therefrom may bepromoted or inhibited, a novel therapeutic agent for degenerative braindisease or central nervous system disease may be developed.

Contents related to genetic engineering technology in the presentinvention may be clearly understood from contents disclosed in a book bySambrook (Sambrook, et al. Molecular Cloning, A Laboratory Manual, ColdSpring Harbor laboratory Press, Cold Spring Harbor, N. Y. (2001)) andFrederick (Frederick M. Ausubel et al., Current protocols in molecularbiology volume 1, 2, 3, John Wiley & Sons, Inc. (1994)).

Advantages and features of the present invention and a method ofachieving them will be clearly understood with reference to exampleswhich will be described in detail. However, the present invention is notlimited to the following disclosed examples but may be implemented indifferent forms. The examples are only provided to completely disclosethe present invention and completely inform those skilled in the art ofthe scope of the present invention, and the present invention is definedby the appended claims.

Example 1 Finding New Secretory FAM19A5 Peptide Using Bioinformatics

The task of screening FAM19A5 genes was performed through abioinformatics approach model. The inventors downloaded open readingframes (ORFs) of about 50,000 species of human genome genes from Ensembl(http://www.ensembl.org/index.html) and UniprotKB(http://www.uniprot.org/uniprot). In order to identify whether geneshaving possible physiological active peptides were among them, genes(secretome) of about 2,000 species that may be secreted from cells werescreened using a Signal P3.0 program. Based on UniprotKB information,screened ORFs were analyzed. The result showed that ORFs of about 600species were determined as genes (peptidome) encoding peptides. Amongthem, 560 species were genes of which functions had been already known,but the remaining 40 species were genes of which functions had not yetbeen discovered and encode new peptides.

FAM19A5 genes among them were found in various vertebrates includinghumans. FAM19A5 includes a gene sequence encoding a typical signalpeptide of an amino terminus as a signal that may be extracellularlysecreted, and subsequently, includes an amino acid sequence of matureFAM19A5. In particular, amino acid sequences of FAM19A5 proteins werevery well conserved among the species (FIG. 1A). A comparative genomicanalysis method described above is recognized as a reliable experimentalmodel capable of verifying whether a newly found novel gene has asubstantial function [Robbins, J Comput Biol 3:465-478, 1996].Meanwhile, according to results of conventional art documents, whilethere is a paper in which CC-chemokine genes were identified to begreatly expressed in brain tissue afflicted with Alzheimer's disease andan identified mechanism in which MIP-la as a CC-chemokine family gene,proliferates glial cells and aggravates degenerative brain disease wasanalyzed, a phylogenetic tree (FIG. 1B) may show that FAM19A familygenes form a distinctly different branch from the CC-chemokine familygenes [MengQi Dia et al., American Journal of Pathology, 1998].

Example 2 Verification of Expression of FAM19A5 Genes in Various Tissuesby Reverse Transcription Polymerase Chain Reaction (RT-PCR)

Six-week old black male mice (C57BL/6, mouse) were bought from DaehanBio Link Co., Ltd. (http://www.dhbiolink.com). The bought mice wereraised in a mouse cages in which adequate feed and water were given, atemperature of 20 to 24° C. was maintained, and a humidity of 40 to 70%was maintained. In addition, these wild-type mice were kept on a 12/12Light/Dark cycle (light on at 8:00 am and light off at 8:00 pm). Allexperiments were designed to use the fewest number of mice, ananesthesia method was performed according to animal experiment ethics tominimize pain of the mice used in the experiment, and this was approvedby Animal Care and Use Committee of the Korea University (KUIACUC-08).

All RNAs of each corresponding tissue from mice were extracted, and thencomplementary DNA (cDNA) was prepared using reverse transcriptase and arandom hexamer. Then, a polymerase chain reaction (PCR) was performedusing a corresponding primer, and an mRNA distribution of mouse tissueswas observed. Information on primers used in PCR is listed in Table 1.

As shown in FIG. 2, all types of FAM19A family genes except the FAM19A3gene were brain-specifically expressed. Also, expression of FAM19Afamily genes was observed even in the early developmental stage.

TABLE 1 PCR Target product Accession gene Primer sequences Size (bps)Positions number FAM19A1 up: ATG GCA ATG GTC TCT GCA 402 437-838 NMdown: TTA GGT TCT TGG GTG AAT 182808 FAM19A2 up: ATG ATC ACC AAG ATG AAT408 1668-2075 NM down: TTA ATG GGT TAC CCT AGT 182807 TG FAM19A3up: ATG GAG AGG CCC ACC AGC 399 590-988 NM down: TTA CCG TGT GAC CTT GGT183224 G FAM19A4 up: ATG AGA GTC TGT GCT AAG T 408 423-830 NMdown: CTA CCG GGT CAC CTT GGT 177233 FAM19A5 up: ATG CAG CTC CTG AAG GCG378 167-544 NM CT 134096 down: TCA GGA GAC CGT GGT GGT CT

Example 3 Verification of Expression of FAM19A5 Genes for EachDevelopmental Stage by In Situ Hybridization

In order to determine expression patterns of FAM19A family genes in thecerebral cortex during the development process, in situ hybridizationwas used to compare amounts of mRNA. Wistar rats were managed in thesame manner as the above method. The rats, on embryonic day 14 (E14)before birth, to 21 days after birth (postnatal day, P21) weresacrificed (decapitation) to obtain the brain from the skull. Sincerats, before birth, have a larger body size than mice, which is adifferent type of experimental rat, rats were easier to handle in theexperiment and used to compare FAM19A5 gene expression for eachdevelopmental stage.

The extracted brain was moved and frozen in a cold isopentane solutionon dry ice. Frozen brain tissues were sliced (sectioned) at 12 μm,attached (Thaw-mounted) to a slide glass coated with TESPA(Sigma-Aldrich Co., Llc., St. Louis, Mo., USA), and fixed in a phosphatebuffered saline (PBS) solution containing 4% paraformaldehyde. Then, anacetylating reaction was performed using 0.1M triethanolamine/0.9% NaCl(pH 8.0) solution containing 0.25% acetic anhydride. Then, ethanol and achloroform solution were used to perform dehydration and degreasingprocess, and drying was performed in air. Meanwhile, the sectionedtissues were hybridized at 55° C. using a probe labeled with ³⁵S, andwashed with a 2×SSC solution at normal temperature. The slide wastreated with RNA-degrading enzyme (RNase), and then the slide wassequentially washed with 2×SSC, 1×SSC, 0.5×SSC, 0.1×SSC solutionscontaining 1 mM dithiothreitol at normal temperature for 10 minuteseach. Finally, the tissue sections were dehydrated, dried in air, andthen the slide glass containing brain tissue sections was exposed to anX-ray film (Biomax MR, Eastman Kodak Co., Rochester, N.Y., USA).

Meanwhile, all RNAs were extracted from the cerebral cortex of adultrats in order to generate a probe, cDNA was prepared using reversetranscriptase and a random hexamer primer, and then T-vector (PromegaCorp., Madison, Wis., USA) cloning was performed. Information on primersused in PCR was listed in Table 2. The cloned T-vector was used as atemplate, an in vitro transcription system (Promega Corp., Madison,Wis., USA) was performed with [³⁵S]UTP (Amersham Pharmacia Biotech Inc.,Piscataway, N.J., USA), and antisense riboprobes of a generated radiolabel were purified and used the present hybridized reaction.

TABLE 2 PCR product Accession Target gene Primer sequences Size (bps)Positions number FAM19A5 up: ATG CAG CTC CTG AAG GCG 399 13-411 NMdown: TCA GGA GAC CGT GGT 001191991 GGT

A dissection plan of the rat's brain was screened by an overall coronalplane and sagital plane from rostral in which the olfactory bulb islocated to caudal in which the cerebellum is located.

As shown in FIG. 3, in mRNA expression of FAM19A family genes, onlyFAM19A5 mRNA was strongly distributed in the ventricular zone and thespinal cord. On embryonic days 14 (E14) and 16 (E16) before birth,FAM19A5 was strongly expressed only in the ventricular zone. FAM19A5 wasstill highly expressed on embryonic day 18 (E18) in the ventricular zoneand the subventricular zone and much more weakly expressed in thecortical plate in which differentiated neurons were included.

FAM19A5 genes were strongly expressed in two regions of the centralnervous system known to have a distributed population of neural stemcells. This means that FAM19A5 proteins are important in formation of acomplete central nervous system and demonstrates for the first time thatFAM19A5 proteins may be involved in generation of neurons and glialcells constituting the central nervous system.

Example 4 Preparation of FAM19A5-Specific Antibody

In order to prepare antibodies capable of specifically recognizingFAM19A5 proteins, short synthetic FAM19A5 was inoculated into a rabbitto obtain polyclonal antibodies. The antibodies specifically recognizedonly FAM19A5 among FAM19A family genes that are overexpressed in HEK293Tcells (FIG. 4A). Also, when treated with N-glicosidase F, 20 kDa band, amature protein of FAM19A5, disappeared, which was determined as anN-glycosylated form (FIG. 4B). Also, each antibody specificallyrecognized HEK293T cells expressing FAM19A5 (His-tagged), which wasobserved using immunocytochemistry (FIG. 4C).

Example 5 Measurement of FAM19A5 Protein Expression During DevelopmentProcess by Immunohistochemistry

In order to determine whether patterns of FAM19A5 protein expressionafter translation similarly appear, immunohistochemistry was used. Micewere managed in the same manner as the above method. Mice on embryonicdays 12 (E12) to 18 (E18) before birth were sacrificed to obtain thebrain from the skull. The extracted brain was fixed (post-fixation) inphosphate buffered saline containing 4% paraformaldehyde for 24 hours to48 hours and treated with phosphate buffered saline containing 30%sucrose for 24 hours. Then, the brain was placed in a mold for braintissues and frozen on dry ice with an OCT composite containing 30% of asugar solution, and kept at −80° C. before the brain was used.

In order to determine the regions and intensity of FAM19A5 proteinexpression in the mouse's brain by immunohistochemistry, anti-FAM19A5that is a polyclonal antibody prepared in Example 4 was used as anantibody that may react with the FAM19A5 protein. The mouse's frozenbrain tissue was sliced at 40 μm using a cryostat microtome. The braintissue sections were washed with a PBS solution for 30 minutes andblocked for one hour using a PBS-T solution (a solution in which 10%TritonX-100 is contained in phosphate buffered saline) containing 10%serum chloride. In the final fluorescence image to be shown, in order toavoid near non-specific antigen-antibody reactions and more accuratelydistinguish an FAM19A5-specific expression region, a ratio of an FAM19A5antibody:blocking solution was set to 1:500. FAM19A5 antibodies andantigens were reacted at 4° C. overnight or at normal temperature (25°C.) for about 3 hours. After a primary antibody-antigen reaction wascompleted, the brain tissue sections were washed three times withphosphate buffered saline for 10 minutes each time. Then, as a secondaryantibody, FITC-coupled anti-rabbit IgG (Invitrogen, USA) was diluted ata ratio of 1:500 and used. After a secondary antibody-antigen reactionwas completed, the brain tissue sections were washed three times with aphosphate buffered saline solution for 10 minutes each time and then thetissue was evenly mounted on the slide glass (mounting). The tissueswere dried at room temperature for about 5 minutes, a crystal/mountsolution (Biomeda Corp., USA) was applied onto the tissues, and a coverglass was used to cover to prepare a specimen. A fluorescence image ofthe prepared specimen was obtained using a confocal microscopy (ZeissLSM 510 confocal microscopy).

Since neural stem cells or neural progenitor cells have an intermediatefilament protein named nestin, nestin was used as a marker [Lendahl etal., Cell 60:585-595, 1990]. In the early developmental stage, it wasobserved that nestin had already been expressed in the neural platebefore a neural tube was formed [Woodbury et al., J Neurosci Res61:364-370, 2000]. Since neuroblasts have a microtubule-associatedprotein doublecortin (DCX), DCX was used as a marker. Nestin and DCXused CY3-coupled anti-mouse and goat IgG (Invitrogen, USA) diluted at aratio of 1:500 as a secondary antibody.

As shown in FIG. 5, interestingly, as in the experiment result using insitu hybridization, FAM19A5 proteins were strongly expressed in theventricular zone, even at a protein level. On embryonic day 12 (E12)which is a period in which progenitor cells being divided are mainlydistributed in the ventricular zone, FAM19A5 peptides were mainlyexpressed throughout the ventricular zone and still highly expressed onembryonic days 14 (E14) and 18 (E18). An amount of expression in thecortical plate was much lower than in the result using in situhybridization. In the progenitor cells containing nestin, FAM19A5proteins were shown in the punctate form. In the neuroblasts containingDCX, weak expression thereof was shown. In some genes, due to apreparing process after transcription or post-translation, levels ofprotein expression and mRNA expression may differ [Wellington et al.,Lab Invest 82:273-283, 2002], but the same expression pattern was shownin the present experiment.

The results of Example 5 in addition to the results of Example 3proposed identification, an expression position, an expression level, oran expression intensity of FAM19A5 proteins in brain tissues during adevelopment process. FAM19A5 was considered to be expressed in neuralstem cells constituting the central nervous system and to be involved ingeneration of neurons and glial cells.

Example 6 Measurement of FAM19A5 Protein Expression in Adult Neural StemCells by Immunohistochemistry

Similar to mice before birth, the region and intensity of FAM19A5protein expression were determined in brains of adult mice byimmunohistochemistry.

Therefore, 4-week old male mice managed in the above method wereintraperitoneally injected with urethane 0.5 cc/100 g for anesthesia,the chest was cut, a Ringer's needle was inserted into the left cardiacventricular to drain blood with 0.9% of saline solution (200 mL), andthe cardiac ventricular was perfused with 0.9% of saline solution (200mL) containing 4% paraformaldehyde and fixed. The brain of the fixedmice was extracted, fixed using phosphate buffered saline containing 4%paraformaldehyde for 24 hours to 48 hours, and treated with phosphatebuffered saline containing 30% of sugar for about 24 hours. Then, thebrain was placed in a mold for brain tissue, frozen on dry ice with anOCT composite containing 30% of a sugar solution, and kept at −80° C.before the brain was used. Similar to mice before birth, in order todetermine the region and intensity of FAM19A5 protein expression throughimmunohistochemistry in the adult mouse's brain, FAM19A5 antibodies wereused. Also, since adult neural stem cells (ependymal cells andastrocytes) have an intermediate filamentprotein named a glialfibrillary acidic protein (GFAP, Invitrogen, USA), GFAP was used as amarker.

As shown in FIG. 6A, similar to the experiment result of thedevelopmental stage, a degree of expression of FAM19A5 was high in thesubventricular zone (SVZ) that is known to have a distributed populationof adult neural stem cells.

Therefore, it may be concluded that expression of FAM19A5 is higher inneural stem cells than neuroblasts.

It was then determined whether an amount of protein of FAM19A5 decreasesthrough differentiated conditions. For this purpose, an experiment wasperformed focusing on SVZ-RMS-OB tract.

Neuroblasts in the SVZ migrated to the olfactory bulb (OB) through arostral migratory stream (RMS) and were finally differentiated intomature interneurons. Since FAM19A5 was more highly expressed in theSVZ-RMS than the OB, it was considered that the amount of proteindecreases through a differentiation process (FIG. 6B).

Example 7 Measurement of FAM19A5 Expression in Neurospheres Developingfrom Adult Neural Stem Cells

Technology for continuously proliferating neural stem cells improves andtherefore a cell mass developing from neural stem cells namedneurospheres may be made. Such technology may be used for variousexperiments and is being used as a useful experiment model that mayreversely track properties of neural stem cells [Reynolds and Weiss,Science 255:1707-1710, 1992; Reynolds and Weiss, Dev Biol 275:1-13,1996].

In order to obtain adult neural stem cells, brains were extracted from3-week to 8-week old male mice. In order to separate the subventricularzone known to have an adult neural stem cell population, brain matriceswere used. Tissues were dissociated into single cells using proteasesuch as dispase (Invitrogen, USA) and papain (Worthington BiochemicalCorp., USA). A growth factor such as an epidermal growth factor (EGF,Invitrogen) and a basic fibroblast growth factor (bFGF, Invitrogen) wasadded to a culture solution, and cells were selectively proliferated toform neurospheres. In addition to adult neural stem cells, a cerebralcortex was separated from a brain of the mouse on embryonic day 12 (E12)before birth, embryonic neural stem cells were selectively culturedusing the same method to obtain neurospheres.

Neurospheres composed of adult neural stem cells and neurospherescomposed of embryonic neural stem cells were fixed in a culture plateusing laminin (Invitrogen, USA) serving as a cell adhesion protein andthen immunocytochemistry was performed in order to determine whetherFAM19A5 proteins are expressed. The result was fixed in phosphatebuffered saline containing 4% paraformaldehyde for 15 minutes andpermeabilized with a PBS-T solution (a solution in which 0.5%TritonX-100 is contained in a phosphate buffered saline) for 5 minutes.After blocking for 30 minutes was performed, an antigen-antibodyreaction was performed, and a dapi staining method was used to observenuclei.

FAM19A5 proteins were expressed in most neurospheres. Since the proteinsare secretory proteins, the proteins were stained in the punctate formin cytoplasm (FIG. 7).

In addition, in order to know properties of cells expressing FAM19A5proteins, neurospheres were simultaneously stained with various markersof neural stem cells.

As a result, cells expressing FAM19A5 proteins simultaneously expressednestin (FIG. 8A). This indicates that neurospheres obtained from neuralstem cells are used as a good experiment model for studying FAM19A5.

Also, in order to verify whether FAM19A5 gene expression in neurospheresis stronger than gene expression of other types of the same family, allRNAs were extracted from neurospheres developed from adult neural stemcells. Then, cDNA was prepared using reverse transcriptase and a randomhexamer. PCR was performed using a corresponding primer, and an FAM19A5mRNA distribution in neurospheres was observed. Information on primersused in PCR was listed in Table 1.

As shown in FIG. 8B, FAM19A5 mRNA among FAM19A family genes was moresignificantly distributed than the other types.

In addition to RT-PCR, a microarray was used to compare degrees ofexpression of FAM19A family genes. Production of cDNA and labeled-cRNAand a hybridized reaction with an Affymetrix MOE430 v2.0 GeneChip (46 kprobe-sets) were performed according to a basic protocol available fromAffymetrix, Inc. (www.affymetrix.com). A fluorescent label was used incDNA synthesis for easy analysis and ChipInspector software (GenomatixSoftware GmbH) was used for statistical analysis of the amount ofexpression.

As shown in FIG. 8C, similar to the results in RT-PCR, the amount ofexpression of FAM19A5 genes was significantly higher than that of othertypes of genes. In addition, a normalized level is from 4 to 14. Inconsideration of the fact that a gene distribution of level 10 or moreis very rare, the result indicates that FAM19A5 is a gene showing strongexpression in neurospheres.

Results of Example 6 and Example 7 strongly suggest that FAM19A5 mayserve as an important material in functions of adult neural stem cellsand embryonic neural stem cells or in a differentiation process intoother types of cells generated therefrom.

Example 8 Numerical Change in Generated Astrocytes According to Analysisof Specific Markers of Neurons and Glial Cells after NeutralizationAction of Antibody Against FAM19A5

In order to determine whether FAM19A5 proteins generated and secretedfrom neural stem cells influence the generation of cells differentiatedtherefrom, an antibody specific to FAM19A5 was used.

In order to perform a differentiation test, neurospheres weredissociated into single cells using Accutase (Innovative CellTechnologies Inc., USA). 50,000 cells were put into each well of a24-well plate and maintained in a culture solution containing a growthfactor for a day, for stabilization. On the next day, the solution waschanged to a differentiation culture solution containing a factorpromoting differentiation. Differentiation was induced for 6 days, andFAM19A5 antibodies (500 ng/mL) were simultaneously added as a treatmentevery day. Western blotting and immunocytochemistry using markerslabeling three types of nervous system cells including neurons,astrocytes, and oligodendrocytes were performed.

As shown in FIG. 9, interestingly, in an experimental group using acorresponding antibody inducing a neutralization action of FAM19A5proteins, the number of neurons labeled with Tuj 1 increased about twotimes more than a control group treated with normal Rb IgG, and thenumber of astrocytes labeled with GFAP decreased correspondingly.

As a result, it may be considered that FAM19A5 proteins may serve as afunctional molecule in a differentiation process from stem cells intoother types of cells, and particularly, may be involved in promotion ofastrocyte generation.

Example 9 Influence of FAM19A5 Peptide and Specific Antibody onProliferation of Neural Stem Cells

In order to determine whether FAM19A5 proteins generated and secretedfrom neural stem cells influence proliferation, peptides and specificantibodies of FAM19A5 were used. In order to perform a proliferationexperiment, neurospheres were dissociated into single cells. 50,000cells were put into each well of a 24-well plate and a culture solutioncontaining a growth factor was treated with peptides or antibodies.Proliferation was induced for 6 days using the growth factor and FAM19A5peptides and specific antibodies were simultaneously treated at 500ng/mL everyday. On the final day, formed neurospheres were dissociatedinto single cells, and the number of cells was measured.

As shown in FIG. 10, it was observed that proliferation of neural stemcells significantly decreased due to FAM19A5 peptides compared to thecontrol group, and when the specific antibody was added as a treatment,proliferation increased.

Example 10 Quantitative Change in FAM19A5 Proteins in Traumatic BrainInjury (TBI) Mice Model

In order to determine whether there is a change in the amounts ofFAM19A5 proteins after brain injury, a traumatic brain injury model wasused. The head of an 8-week-old mouse was fixed and then an iron bar,sufficiently cooled by liquid nitrogen, was placed on the right side ofthe skull for one minute. The mouse's skin was sutured through anoperation, and the mouse was managed in the same manner as normal micefor 7 days [Moon et al., Neuro report 22:304-308].

Seven days later, intraperitoneal anesthesia was performed on the mouse,the chest was cut, a Ringer's needle was inserted into a left cardiacventricular to drain blood with 0.9% of normal saline (200 mL), and thenthe cardiac ventricular was perfused with 0.9% of saline solution (200mL) containing 4% paraformaldehyde and fixed. The brain of the fixedmouse was extracted, fixed in phosphate buffered saline containing 4%paraformaldehyde for 24 hours to 48 hours, and treated with phosphatebuffered saline containing 30% of sugar for about 24 hours. Then, thebrain was placed in a mold for brain tissue, frozen on dry ice with anOCT composite containing 30% of a sugar solution, and kept at −80° C.before the brain was used. The mouse's frozen brain tissue was sliced at40 μm using a cryostat microtome and then immunohistochemistry wasperformed.

When external damage is applied, mature astrocytes become radial glialcells through a reverse differentiation process. These types of cellsexpress a progenitor cell marker named nestin and generate glial cellsat a position thereof

As shown in FIG. 11A, a significant increase in the number of cellsexpressing FAM19A5 proteins was observed in a damaged region (penumbra).Radial glial cells in the damaged region express nestin serving as amarker and simultaneously express FAM19A5, and the amount of proteinssignificantly increased compared to a control group having no damage.

Also, although it is a very low ratio, neuroblasts migrated to the braininjury region from the subventricular zone through the corpus collosum(CC) did not express FAM19A5 peptides. In addition to the damagedregion, in a periphery region of the subventricular zone in which aneural stem cell population is positioned, the number of cellsexpressing FAM19A5 proteins increased, and these simultaneouslyexpressed GFAP serving as a marker of astrocytes. As a result, it wasconsidered that FAM19A5 peptides generated from neural stem cells aremore likely to be involved in generation of astrocytes than generationof neurons.

Meanwhile, a secretory factor of FAM19A5 is likely to be leaked intoblood while the blood-brain barrier is damaged after brain injury. Inthis case, by determining expression or the degree of expression, adiagnosis marker capable of determining occurrence, progress, andalleviation of brain injury disease or brain disease may be developed.In order to know the possibility thereof, blood was obtained from normalmice and mice 7 days after brain injury, that were considered to havethe highest expression of FAM19A5, and coagulated. Then, only serum wasseparated and a radioimmunoassay was performed.

The amount of proteins in serum was measured using a standard curve. Asa result, surprisingly, 7 times or more FAM19A5 proteins were detectedin the serum of the mice 7 days after brain injury compared to normalmice (FIG. 11B).

Example 11 Quantitative Change in FAM19A5 Proteins Over Time afterTraumatic Brain Injury (TBI)

A quantitative change in FAM19A5 proteins over time after traumaticbrain injury was observed in only reactive astrocytes expressing GFAP.

As shown in FIG. 12, it was determined that expression of FAM19A5 wasrelatively low in astrocytes labeled with GFAP 3 days after damage,expression started to increase after 5 days, and continuously increasedfor 7 days.

Example 12 Measurement of Quantitative Increase in FAM19A5 ProteinsShown in Amyotrophic Lateral Sclerosis (ALS)

In ALS model animal mSOD1 G93A Tg mice, immunostaining was performed ontissues in a period in which ALS symptoms were expressed. As shown inFIG. 13A, the results showed that expression of FAM19A5 increased to avery high level in the spinal cord of the mSOD1 G93A mouse compared tothe same-aged mouse. Such an increase in expression was stronglyobserved in the ventral horn in which motor neurons particularlydegenerated and died due to ALS are distributed. In this period, in thespinal cord of the mSOD1 G93A mouse, proliferation of glial cells wasobserved. Such a pathological modification process was also detectedthrough GFAP double staining. Enlarged pictures on the bottom arehigh-magnification images of the ventral horn of the mSOD1 G93A mouse.It can be seen that most of the glial cells labeled with GFAP show ahigh level of FAM19A5 expression. Meanwhile, cells (indicated by anarrow) distributed at the center of the picture are considered asdegenerative motor neurons since it had a circular nucleus and was notstained with GFAP. Even in this case, strong expression of FAM19A5 wasobserved. Nuclei were counter-labeled with blue fluorescence by Hoechststaining.

In addition, a change in expression was observed by immunoblotting. Theresult showed that expression of FAM19A5 increased to a very high levelin the spinal cord of the ALS model mice (TG) compared to the wild-type(WT) mice (FIG. 13B).

A radioimmunoassay was performed in the same manner as in Example 10.The result showed that the amount of FAM19A5 proteins in the serum ofthe ALS model mice was detected at 3 times that of the normal mice ormore (FIG. 13C).

Therefore, FAM19A5 detected in a brain injury model including traumaticbrain injury and spinal cord damage disease models including amyotrophiclateral sclerosis may be developed as a labeling material of centralnervous system damage.

Example 13 Delay Effect of Reactive Astrocytosis by FAM19A5 AntibodyTreatment after Traumatic Brain Injury (TBI)

In order to determine a function of FAM19A5 proteins of which expressionincreased after brain injury is induced, FAM19A5 antibodies wereinjected into the vein of the mouse's tail one day after damage wasinduced. It was considered that, when traumatic brain injury is applied,the blood-brain barrier near the damaged region may be damaged andantibodies may be introduced into surrounding brain tissues.

Only when antibodies of FAM19A5 were injected, a fluorescence signal dueto secondary antibodies was observed (FIG. 14).

Antibodies were injected one day after damage. After 3, 5, and 7 dayshad elapsed from the damage-inducing day, changes were observed usingvarious cell markers.

As shown in FIG. 15, in a mice model into which FAM19A5 antibodies wereinjected after 3 days had elapsed, generation of reactive astrocytesexpressing GFAP was inhibited in the vicinity of damaged tissues,compared to a control group into which normal rabbit IgG was injected.Such a phenomenon was more significantly shown after 5 days had elapsedand weakly maintained even after 7 days had elapsed. Therefore, it isconsidered that inhibition of secreted FAM19A5 using antibodiesinfluences surrounding cells, and particularly, delays reactiveastrocytosis occurring after damage.

Meanwhile, reactive astrocytes generated after damage secrete a nervegrowth factor that prevents programmed cell death such as GDNF andsimultaneously resumes the uptake of glutamic acid, thereby positivelyacting to reduce the toxic environment around neurons. Therefore, inorder to determine whether a delay in reactive astrocytosis according toFAM19A5 antibodies negatively influences a function for protectingneurons, TUNEL staining was performed.

As shown in FIG. 16, it was determined that cells expressing the neuronmarker, NeuN, were not simultaneously stained with TUNEL, and a loss ofreactive astrocytes does not kill neurons.

According to Example 10, reactive astrocytes generated from the damagedregion after traumatic brain injury strongly expressed FAM19A5 proteins.Based on the result, in a mouse model treated with FAM19A5 antibodiesafter traumatic brain injury, positions of reactive astrocytes in whichFAM19A5 proteins are expressed were determined

As expected, it was observed that astrocytes expressing FAM19A5 proteinswere relatively separately positioned from the damaged region in thedamage model into which FAM19A5 antibodies are injected, compared to acontrol group (FIG. 17).

Example 14 Numerical Decrease in NG2 Oligodendrocyte Progenitor CellsAccording to FAM19A5 Antibody Treatment after Traumatic Brain Injury(TBI)

Using the same experiment method described above, in order to determinewhether FAM19A5 antibodies influence generation of other types of glialcells, staining was performed with several types of markers of glialcells.

When 5 days had elapsed after brain injury, the number ofoligodendrocyte progenitor cells expressing neuron-glial antigen 2(NG2)decreased in the damaged region (FIG. 18A).

Meanwhile, since NG2 cells divided in damaged brain tissues are known tobecome oligodendrocytes that form a mature myelin sheath, matureoligodendrocytes labeled with a myelin basic protein (MBP) were observedand the number thereof also decreased (FIG. 18B).

Therefore, reactivation of FAM19A5 occurring after brain injury promotesproliferation of NG2 progenitor cells and is considered to be involvedin myelinating axons of surrounding neurons.

The present invention has found that FAM19A5, which is a proteinsecreted from neural stem cells and regulates proliferation ordifferentiation of neural stem cells, is overexpressed in the event ofcerebrospinal damage, promotes generation of astrocytes and recuperationof early damaged tissues, and when FAM19A5 is neutralized withantibodies specific to FAM19A5 in damaged tissues, generation ofastrocytes is suppressed. Therefore, FAM19A5 may be used for diagnosis,prevention, or treatment of central nervous system damage, degenerativebrain diseases, or central nervous system diseases.

FAM19A5 of the present invention or an inhibitor thereof may be used asa stem cell proliferation or differentiation regulator, and a diagnostickit, a chip, or a therapeutic agent for central nervous system damage,degenerative brain disease, or central nervous system disease.

What is claimed is:
 1. A composition for regulating proliferation ordifferentiation of stem cells, comprising FAM19A5 (family with sequencesimilarity 19, member A5) or an inhibitor thereof as a proliferation ordifferentiation regulator.
 2. The composition of claim 1, wherein thestem cells are embryonic neural stem cells or adult neural stem cells.3. The composition of claim 1, wherein the inhibitor of FAM19A5 is anyone of an antisense-oligonucleotide, siRNA, shRNA, miRNA or a vectorincluding the same, or antibodies.
 4. A composition for diagnosingcentral nervous system damage, degenerative brain disease, or centralnervous system disease, comprising an agent for measuring mRNA ofFAM19A5 (family with sequence similarity 19, member A5) genes or aprotein level thereof.
 5. The composition of claim 4, wherein the agentfor measuring mRNA of the genes includes an oligonucleotide having asequence complementary to mRNA of the genes.
 6. The composition of claim4, wherein the agent for measuring a protein level includes antibodiesspecific to the protein.
 7. The composition of claim 4, wherein thecentral nervous system damage, the degenerative brain disease, or thecentral nervous system disease includes traumatic brain injury,amyotrophic lateral sclerosis, Alzheimer's disease, Huntington'sdisease, Parkinson's disease, stroke, or brain tumor.
 8. A compositionfor treating early traumatic brain injury, comprising FAM19A5 (familywith sequence similarity 19, member A5).
 9. The composition of claim 8,wherein the composition includes at least one selected from the groupconsisting of natural or recombinant FAM19A5 proteins, transgenic neuralstem cells overexpressing FAM19A5 proteins, and astrocytesdifferentiated from the neural stem cells.
 10. A composition forpreventing or treating degenerative brain disease or central nervoussystem disease, comprising an FAM19A5 (family with sequence similarity19, member A5) inhibitor.
 11. The composition of claim 10, wherein theFAM19A5 inhibitor is any one of an antisense-oligonucleotide, siRNA,shRNA, miRNA or a vector including the same, or antibodies.
 12. Thecomposition of claim 10, further comprising embryonic neural stem cellsor adult neural stem cells.
 13. A method of screening for a preventiveor therapeutic medicine for brain disease or central nervous systemdisease, comprising contacting FAM19A5 (family with sequence similarity19, member A5) genes with a candidate material in vitro, and determiningwhether the candidate material promotes or inhibits expression of thegenes.
 14. A method of screening for a preventive or therapeuticmedicine for brain disease or central nervous system disease,comprising: contacting FAM19A5 (family with sequence similarity 19,member A5) proteins with a candidate material in vitro, and determiningwhether the candidate material promotes or inhibits a function or anactivity of the protein.